This here is the hole truth and
nothing but the hole truth so help me. . . somebody.

It has been thought that the holes
in the radiator support allowing passage of the oil cooler lines were the tell tale
sign of a factory oil cooler car. It was said the upper hole had to be a smooth, factory
cut, oval. The lower oil cooler line hole should be round and should occur in the beveled
area just above the lower oval A/C hole. The warning was if you saw any jagged holes or a
simple rectangular upper hole that was formed by removing a knockout plate, beware, it's
not a factory car. Recent research and photographic proof from Registry members has proven
that this "old Mustanger's" tale just like other old Mustanger's tales isn't
true. Never say never and never say all (or always).

Above: Hole thought to be the proper upper oil line hole on
oil cooler cars.

Above: Original knock-out plate.

Let's go back in time
to the year 1967. Shown to the right is a scan of the Ford print for the 1967/1968 Mustang
radiator support. Why 1967/68 you ask? There were no oil coolers on those cars. Yes,
that's right. Look at the drawing. You will see the familiar "look" of an oval
hole. You see the note in the upper right side pointing to the oval hole? It reads,
"2 DRILL DIMPLES 1.50 DIA. FOR A/C INSTALLATION." If this is supposed to be a
clean, oval hole, why does it need two (2) drill dimples? Notice the other note,
"LANCE THIS DISTANCE BOTH SIDES." That is to form the knock out. Also note the
dimension, 1.74. and the .75R (radius) on the oval. 2 x .75 =1.50. Not a coincidence.

Above: 1967/68
drawing

Moving on to
1969/1970. This is a scan of the 1969/70 radiator support drawing. Notice there's no oval
hole. Well, there's no oval hole shown on the drawing. There is, however, the same note in
the lower left, "2 DRILL DIMPLES 1.50 DIA. FOR A/C INSTALLATION." Look closely
and you can see the two dimples. The arrow from the note points to the lower dimple. Look
closely again and you will see an arrow pointing into the side of what looks like a square
with the same dimension, 1.74. The line for that arrow goes off to a side note where it
says. . .

Above: 1969/70
drawing

"LANCE THIS
DISTANCE BOTH SIDES."

So,
the 1969/70 drawing has the same notes and dimensions as the 1967/68 except for the oval
hole. What about the hole? The 1967/68 drawing is probably technically incorrect because
it depicts an oval hole which did not actually exist as the part was stamped at the
stamping plant without the oval hole. Why put in the dimples and a drill note if you were
going to stamp out the entire oval? The lancing formed the rectangular knockout.

Above: 1969/70
drawing side note

With all
that in mind, what the registry has found is that the upper "oval hole" was not
a clean, stamped hole. How was it made? The oval hole was made by a 1.50" drill bit
or hole saw centered on the dimples and done by an assembly worker. Two runs with a drill
and knocking out the remaining material in the center between the holes created the oval
hole. Trouble here is, there were humans involved. Where there are humans involved there
will be errors. Not all oval holes are created equally. See the photos below from
documented factory Drag Pack option cars. (BOSS 429, 428 SCJs and Cougars).

photos
by Frank Bowers

1969 BOSS 429 - top
and bottom drilled off center

1969 428 SCJ -
missing top cut

1970 Cougar
Eliminator - not quite complete

"Okay,
there is a round hole on the slanted surface just above the lower oval hole. When you see
that round hole, you know it came from the factory with an oil cooler." Look
back up at the 1969/70 print scan. See the ellipse cut in half at the bottom? You remember
your geometry, right? A circle shown in a slanted view becomes an ellipse, right?

Here is another view
of that same hole. If you look closely you can see Section P is cut through this hole.

Right: 1969/70
drawing lower portion

Here is Section P
shown in another location on the print showing the true round hole. See the arrow coming
in from the upper left?

Right: 1969/70
drawing lower round hole

The note that arrow
points from (to) says, "1.250 DIA HOLE DRILL AT ASSY FOR OIL LINE". ASSY is the
Ford abbreviation for ASSEMBLY. The "BV" in the circle is a change notation.
Change note BV shows this hole was
added for the 1970 MY. You should not
see this hole on a 1969 car. But remember, never say never.

So... this hole wasn't a round, stamped hole either.
It too was drilled by a line worker.

Right: 1969/70
lower round hole note

Jagged
holes and radiator supports lacking holes have been found. Here again, there are humans
involved and there will be "assembly variations."

photos by Frank Bowers

Above: 1969 BOSS 429

Above right: 1970
Cougar Eliminator

Right: 1969 428
SCJ

The whole truth is the
holes in the radiator support don't mean a thing when comes to identifying a factory oil
cooler car. The upper holes can be crooked or jagged or just the rectangle from the knock
out. (Wonder how they knocked that out if they were supposed to drill it? Very creative
line workers no doubt.) The lower hole can be perfectly round, rough and oblong or the
lower oval might be extended from the drilling or the hole might not even be there at all.
There may be holes in cars that were never intended to get an oil cooler. So the line
workers drilled a few extra holes. Weight savings. Gets better gas mileage.